How Brain Abscesses Affect Big Bucks

Zombie whitetails aren’t the norm but occasionally one will have a problem with what biologists identify as a brain abscess and may indeed exhibit zombie-like traits.

By Alan Clemons

Chas Moore, Wildlife Biologist, with the Alabama Division of Wildlife and Freshwater Fisheries, wrote about the problem of brain abscesses. They’re seen most often in bucks in the southeast and east from September to April when the deer are shedding the velvet from their newly-grown racks on through spring when the antlers fall off.

This photo shows a white-tailed buck with a brain abscess extending from an antler pedicle through the skull and into the brain.

“Nearly 90 percent of all documented cases of brain abscesses have been from bucks, especially mature bucks greater than 3.5 years old,” Moore wrote. “Some researchers have documented that brain abscesses can account for over half of all cases of natural mortality among 4.5 year old or older bucks. Because brain abscesses are usually fatal, this is a significant non-hunting mortality factor that should be considered in any quality deer management program where mature bucks are desired.”

During this period, which includes sparring or fighting, injuries to the pedicle or skin may allow bacteria to enter the brain. Infection can lead to abnormal activity, loss of appetite, blindness and fearlessness of humans or predators. A stinking “pocket of pus” affecting the brain often is discovered by hunters, processors or taxidermists. The meat is safe to eat, Moore notes.

Moore again: “Any number of bacteria can be responsible for this condition, but Arcanobacterium pyogenes is most commonly found in samples. Once the bacterium enters the brain, a pocket of puss forms and enlarges until the deer dies. Deer with this condition often walk in circles and appear to be completely unaware of their surroundings. They may even come toward humans when approached. Some go blind. Most will be emaciated. These signs become much more evident as the condition worsens, eventually leading to death for the deer.”

If you harvest an adult buck with pus weeping from antler pedicles or eye sockets, the deer may have this bacterial infection. Though the meat may be contaminated with the CAS-causing bacteria, the infection is usually limited to the head. No part of the head should be eaten. The other meat is likely safe to eat, as normal cooking temperatures will destroy the bacteria.

Zombie deer? Well, yeah, sort of. If you see a deer “acting funny” then there’s a chance it could be due to an abscess. It’s just part of nature.

Editor’s note: If you kill an adult buck with pus weeping from antler pedicles or eye sockets, the deer may have this bacterial infection. Though the meat may be contaminated with the CAS-causing bacteria, the infection is usually limited to the head. No part of the head should be eaten. The other meat is likely safe to eat, as normal cooking temperatures will destroy the bacteria.